Effect of calcium and nitrogen spraying on growth, yield and BER disorder of watermelon “Top yield” var. (Citrullus lanatus) in Sulaimani Governorate

Original: 25/11/2017 Revised: 25/01/2018 Accepted: 09/02/2018 Published online: This study was carried out at Kanipanka Research Station / Sulaymani during growing season of (2015) to study the effect of nitrogen and calcium spraying and their interaction on growth, yield and Blossom-end rot% incidence of watermelon plant (“Top yield” var.).This study included spraying nitrogen as three concentrations (0, 200 and 400 mg N l -1 ) using urea fertilizer and spraying calcium as four concentrations (0, 100, 300, 600 mg Ca l -1 ) concentrations using CaCl2. The study's characters were reproductive growth, yield and Blossom-end rot percentage (BER %). The results showed that maximum infected fruits % (32.26 %) was obtained from Ca0. While Ca3 (600 mg l -1 ) gave minimum BER infected fruit (6.64 %) and maximum number of flower.plant -1 (10.1), yield plant -1 (4.98 kg), fruit weight (3.86 kg) and total yield (53.17 t ha -1 ).N2 (400mg l -1 ) gave highest yield plant -1 (4.60 kg) and total yield.ha -1 (48.11t). Nitrogen and Calcium combination (400mg l -1 N x 600mg l -1 Ca) gave the highest number of flower plant -1 (10.30) and minimum BER% (4.42%). (200mg l -1 N x control Ca) gave the highest yield plant -1 (5.36kg) and total yield ha -1 (55.06t), while (200mg l -1